Over an internet, network computers or network devices (i.e., clients) issue requests for applications such as multimedia real-time download, large file transfer, or interactive sessions that are placed with another computer (i.e., server). For example, a request from a client can be made for a video broadcast from a CNN server. Such video transfers require sustained availability of bandwidth for the duration of transfer. Since client requests are independent of each other, many client requests line up at the server at peak hours of operation. When the server capacity or the network capacity is exceeded, any further client requests result in a denial of service (DOS). In such a case, clients either usually back off and try again later, or give up on the request entirely. In either case, while existing clients are being timed out, new clients are likely to request the same resources independent of each other. The new requests will further add to previous requests and retries. Persistent requests keep the server and network bandwidth fully loaded and on the verge of breakdown. The network can breakdown at the server or any other point along the network.
Referring to FIG. 1, a conventional internet system 10 is shown. The system 10 includes a number of clients 12a–12n, an internet backbone portion 14 and a server 16. The system 10 illustrates a conventional internet sequence of events for network access. The clients 12a–12n request information from the server 16. If the server 16 reaches capacity and denies connection, bandwidth issues result. The denied clients 12a–12n can wait a period of time and return to the server 16 later or give up entirely.
The clients 12a–12n are not informed of the level of network congestion, or the number of requests already pending at the server 16. All requests and retries come asynchronously and are not efficiently handled by the system 10.
The server 16 is never able to surpass a maximum bandwidth usage level, since new requests constantly back up. Network and service providers must then plan for a worst case need of bandwidth. The conventional internet system 10 does not provide for orderly delivery of bandwidth among subscribers and results in expensive network resources between the server 16 and the clients 12a–12n for installation and operation.
Conventional methods have been proposed to solve bandwidth bottleneck issues. One such method, connection admission control (CAC), employs admission and reservation granted in advance. The server then refuses to allow any newer client entry. Interconnected with the CAC is a method for network bandwidth management, resource reservation protocol (RSVP). The RSVP method reserves network traffic bandwidth at all the nodes between a client and a server. However, CAC with or without RSVP, is asynchronous to incoming client requests. The bandwidth becomes unmanageable, since new clients have no information about network loading.
It is generally desirable to provide a cost effective system for reducing network congestion configured to handle numerous requests.